Floribunda Rose Plant Named &#39;GRAdkpk&#39;

ABSTRACT

‘GRAdkpk’ is a new and distinct floribunda type  Rosa  hybrid cultivar which is characterized by the combination of an upright to semi-weeping growth habit, excellent resistance to  Diplocarpon rosae , nearly continuous flowering, lavender pink double-type flowers which fade to mauve pink, a strong rose fragrance, and the stability of these characteristics from generation to generation. The new cultivar is generally suited to landscape applications.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to the Australian Plant Breeder's Rights application number 2015/088, filed on Apr. 27, 2015, which is herein incorporated by reference.

Latin name of genus and species: The Latin name of the genus and species of the novel variety disclosed herein is Rosa hybrid.

Variety denomination: The inventive variety of Rosa hybrid disclosed herein has been given the variety denomination ‘GRAdkpk’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct Rosa hybrid, floribunda rose cultivar, which has been given the variety denomination of ‘GRAdkpk’. Its market class is PLT/141.

Parentage: ‘GRAdkpk’ is a seedling selection which resulted from the controlled cross-pollination of an unnamed Rosa hybrid female breeding line and an unnamed Rosa hybrid male breeding line. Both parents, developed by the same inventor and never commercially released, exhibited traits deemed commercially significant and desirable.

After many years of trialing, the female parent was confirmed to possess a combination of desirable traits such as complete resistance to rose black spot disease, complete resistance to powdery mildew, and flowers with a strong citrus-like perfume borne on a bushy plant growing to 1.2 m tall and wide. The male parent was selected for use in breeding after trialing confirmed the presence of strong true-rose perfume and a bright, modern flower color. During the summer of 2010, the female parent was emasculated and was manually pollinated with pollen from the male parent. In autumn of 2010, seed was collected from hips produced by the female parent and a number of seedlings were grown to a mature size, including the claimed plant. These progeny were further evaluated for desirable traits such as black spot disease resistance and strong perfume, and in June of 2011 the claimed plant was first observed. In January of 2013, after further evaluation for desirable traits, the claimed plant was deemed to be garden-worthy and suited to widespread cultivation. It was given the denomination, ‘GRAdkpk’.

Asexual Reproduction: Asexual propagation of ‘GRAdkpk’, by way of softwood stem cuttings, was first performed in May of 2011 at the inventor's nursery in Highfields, Australia. Through more than twelve subsequent generations, the unique features of this cultivar have proven to be stable and true to type.

SUMMARY OF THE INVENTION

The following characteristics have been repeatedly observed and represent the distinguishing characteristics of the new Rosa cultivar ‘GRAdkpk’. These traits, in combination, distinguish ‘GRAdkpk’ as a new and distinct cultivar.

-   -   1. Rosa hybrid ‘GRAdkpk’ exhibits an upright to semi-weeping         growth habit; and     -   2. Rosa hybrid ‘GRAdkpk’ exhibits excellent resistance to the         plant pathogen, Diplocarpon rosae, commonly referred to as rose         black spot disease; and     -   3. Rosa hybrid ‘GRAdkpk’ exhibits nearly continuous flowering;         and     -   4. Rosa hybrid ‘GRAdkpk’ exhibits a double flower type; and     -   5. Rosa hybrid ‘GRAdkpk’ exhibits lavender pink flowers which         fade to mauve pink; and     -   6. Rosa hybrid ‘GRAdkpk’ exhibits flowers with a strong rose         fragrance.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrates, as nearly true as it is reasonably possible to make the same in color photographs of this type, an exemplary 15 month old ‘GRAdkpk’ plant grown outdoors at the inventor's commercial nursery in Highfields, Australia.

FIG. 2 illustrates, as nearly true as it is reasonably possible to make the same in color photographs of this type, the typical foliage and flower of ‘GRAdkpk’.

DETAILED BOTANICAL DESCRIPTION

The following observations and measurements, made in February of 2016, describe averages of two own-root specimens of one year old ‘GRAdkpk’ plants. The plants were grown outdoors in 20 cm containers, in a soilless pine bark based growing media, at the inventor's nursery in Highfields, Australia. No shade or supplemental light was provided. Temperatures ranged from approximately 17 to 35 degrees Celsius during the day and 7 to 18 degrees Celsius at night. Standard practices for irrigation, fertilizer and pest control were applied at appropriate times during the growing season. The plants were pruned three times during the growing season using accepted techniques for rose pruning.

Those skilled in the art will appreciate that certain characteristics will vary with older or, conversely, with younger plants. ‘GRAdkpk’ has not been observed under all possible environmental conditions. Where dimensions, sizes, colors and other characteristics are given, it is to be understood that such characteristics are approximations or averages set forth as accurately as practicable. The phenotype of the variety may differ from the descriptions set forth herein with variations in environmental, climatic and cultural conditions. Color notations are based on The Royal Horticultural Society Colour Chart, The Royal Horticultural Society, London, 2007 Fifth Edition except where common terms of color are used.

A botanical description of ‘GRAdkpk’ and comparisons with the parents and the most similar commercial cultivar of Rosa hybrid are provided below.

-   General plant description:     -   -   Growth habit.—Upright to semi-weeping.         -   Growth rate.—Awl uximately 1 years to reach 40 cm.         -   Dimensions.—40 cm tall and 40 cm wide.         -   Environmental tolerance.—Very good heat tolerance; cold             hardiness is unknown.         -   Disease resistance.—Excellent resistance to powdery mildew             (Sphaerotheca pannosa) and blackspot (Diplocarpon rosae).         -   Propagation.—Technique — Softwood stem cuttings. Time to             initiate roots — About 13 days at approximately 21 degrees             Celsius at root zone and 18 degrees Celsius ambient             temperature. Time to produce a rooted cutting — About 25             days at approximately 21 degrees Celsius at root zone and 18             degrees Celsius ambient temperature. -   Root system: White fibrous roots with many root hairs extending from     lesser roots in a featherlike arrangement. -   Branches:     -   -   Branching habit.—Irregular branching from mature branches,             breaking first from the uppermost buds near the apex of each             shoot.         -   Quantity.—Numerous.         -   General dimensions.—Approximately 15 cm long; 0.7 cm in             diameter near the base and tapering to 0.5 cm.         -   Immature branches.—Diameter — Approximately 0.4 cm. Texture             and pubescence — Smooth with prickles; moderately to heavily             pubescent. Color — Near RHS 142B. Prickles — Density —             Moderate. Color — Near RHS 165C. Shape — Concave. Texture —             Smooth.         -   Mature branches.—Diameter — Approximately 0.7 cm, after one             year. Texture and pubescence — Smooth with prickles;             glabrous. Color — Near RHS 143B. Prickles — Density —             Moderate. Color — Near RHS 144C Shape — Concave. Texture —             Smooth. -   Leaves:     -   -   Arrangement.—Alternate imparipinnate compound leaves.         -   Quantity.—Approximately 6 per mature branch.         -   Attachment.—Petiolate.         -   Leaf internode length.—2.2 cm.         -   Dimensions.—Approximately 8 cm long and 6 cm wide.         -   Petiole.—Dimensions — Average of 1.0 to 2.0 cm long and 0.1             to 0.2 cm wide. Color — Near RHS 142C. Texture and             pubescence — Rough and glabrous. Prickles — Small blunt             prickle is present. Stipitate glands — Not present.         -   Stipule.—Dimensions — 1.0 cm long and 0.4 cm wide. Color —             Near RHS 142C. Texture and pubescence — Smooth and glabrous.             Margins — Ciliate. Apex — Acuminate. Base — Winged. Prickles             — Not present. Stipitate glands — Not present.         -   Rachis.—Dimensions — 1.5 cm long and 0.2 cm wide. Color —             Near RHS N138C. Prickles — Present. Stipitate glands — Not             present.         -   Leaflets.—Quantity — Five leaflets on axillary leaves.             Dimensions — Average size of the terminal leaflet is 3.5 cm             long and 3.0 cm wide. Shape — Ovate. Apex — Acuminate. Base             — Ovate. Margins — Serrated. Texture, pubescence and luster,             adaxial surface — Smooth, glabrous, and semi-glossy.             Texture, pubescence and luster, abaxial surface — Rough,             glabrous, and matte. Juvenile foliage color, adaxial surface             — Near RHS 143A, with anthocyanin intonations, near RHS 53A,             at the margins and midrib. Juvenile foliage color, abaxial             surface — Near RHS 139C, with anthocyanin intonations, RHS             53A. Mature foliage color, adaxial surface — Near RHS N138B.             Mature foliage color, abaxial surface — Near RHS 139C.             Venation — Pinnate. Venation color, adaxial surface — Near             RHS N138B. Venation color, abaxial surface — Near RHS 139D.             Petiolule — Dimensions — 0.3 cm long and 0.1 cm wide. Color             — Near RHS 144D. Prickles — Not present. Texture — Smooth. -   Inflorescence:     -   -   Inflorescence type.—Terminal corymb consisting of             approximately 2 to 6 pedicellate flowers.         -   Blooming habit.—Almost continuous from October through June             in the southern hemisphere.         -   Time to flower.—6 to 8 weeks for a new stem to mature and             flowering begins to occur once a stem matures.         -   Dimensions.—17 cm from the base of the base of the lowest             pedicel to the farthest distal flower and the width from             farthest outstretched flower on one side of the             inflorescence to the farthest outstretched flower on the             opposite side is 22 cm.         -   Peduncle.—Dimensions — 4.5 cm long and 0.2 cm in diameter.             Color — Near RHS 144A. Strength — Strong. Texture and             pubescence — Rough and glabrous. Prickles — Not present. -   Bud:     -   -   Shape.—Ovate.         -   Size.—2.0 cm long and 1.5 cm in diameter.         -   Color.—Near RHS 13/D. -   Flower:     -   -   Pedicel.—Dimensions — 5 cm. Color — Near RHS 144A. Strength             — Strong. Texture — Rough.         -   Calyx.—General — Comprised of five polysepalous sepals, with             strong foliaceous appendages present on all sepals. Diameter             of calyx — 0.4 cm. Sepals — Color, interior surface — RHS             130D. Color, exterior surface — RHS 137D. Dimensions — 2.0             cm long and 0.6 cm wide. Apex — Acuminate. Base — Flat at             union with receptacle. Quantity — Five. Pubescence — Densely             puberulent. Margins — Two to three strong foliaceous             appendages. Stipitate glands — Not present.         -   Corolla.—General shape of corolla — Cupped and well-rounded             at anthesis; aging to a loose whorl. Rate of opening — 6             days from bud to anthesis. Dimensions — Approximately 8 cm             in diameter and 5 cm deep. Fragrance — Strong rose scent.             Lastingness — On the plant for 5 days after anthesis.             Persistence — Self-cleaning. Petals — Petal count — Exhibits             double flowers with approximately 36 petals under normal             conditions. Petal arrangement — Irregularly rounded whorl,             with loose outer whorl. Dimensions — 3.2 cm long and 2.2 cm             wide. Petal shape — Obovate. Apex — Rounded to cordate. Base             — Flattened, then obtuse. Petal reflex — Slightly reflexed             at apex. Petal margin — Entire; slightly undulating. Texture             — Soft. Aspect — Slightly ruffled. Petal color, upon opening             — Upper surface — Near RHS 67B. Lower surface — Near RHS             N57C. Petal color, at anthesis — Upper surface — Near RHS             73A. Lower surface — Near RHS 73B. Fading — Near RHS 52C. -   Reproductive organs:     -   -   Stamens.—Quantity — Approximately 30. Anthers — Shape —             Narrow ovate. Length — 0.1 cm. Color — Near RHS 21B. Pollen             — Many. Pollen Color — Near RHS 3A. Filaments — Color — Near             RHS 8D. Length — Approximately 0.7 cm. Pistils — Quantity —             Approximately 50. Length — Approximately 0.8 cm. Stigma —             Shape — Ovate. Color — Near RHS 11B. Style — Length —             Approximately 0.3 cm long. Color — Near RHS 18D.         -   Ovary.—Dimensions — 0.5 cm long and 0.3 cm wide. Color —             Near RHS 3D.         -   Receptacle.—Shape — Pitcher-shaped. Dimensions — 0.5 cm high             and 0.5 cm wide. Color — Near RHS 137D. -   Hip and seed:     -   -   Hip.—Shape — Rounded. Dimensions — 1.5 cm long and 1.7 cm             wide. Texture — Smooth. Color — Near RHS 138B.         -   Seed.—Not present. -   Comparisons with the parents: The new rose plant ‘GRAdkpk’ may be     distinguished from its seed parent, an unnamed breeding line, by the     following combination of characteristics:     -   1. The flowers of ‘GRAdkpk’ exhibit a distinct lavender pink         general tonality with a rounded form and center petals remaining         erect and cupped for some period of time after anthesis, whereas         the flowers of the seed parent exhibit a soft pink general         tonality and loose, open flowers.     -   2. ‘GRAdkpk’ exhibits an upright to semi-weeping growth habit,         whereas the seed parent exhibits an upright growth habit. The         new rose plant ‘GRAdkpk’ may be distinguished from its pollen         parent, an unnamed breeding line, by the following combination         of characteristics:     -   1. The flowers of ‘GRAdkpk’ exhibit a distinct lavender pink         general tonality with a rounded form and center petals remaining         erect and cupped for some period of time after anthesis, whereas         the flowers of the pollen parent exhibit a purple general         tonality.     -   2. ‘GRAdkpk’ exhibits an upright to semi-weeping growth habit,         whereas the pollen parent exhibits an upright growth habit.     -   3. ‘GRAdkpk’ exhibits juvenile foliage colored near RHS 143A         with anthocyanin intonations, whereas the pollen parent exhibits         juvenile foliage colored near RHS 137C with no anthocyanin         intonations. -   Comparisons with the most similar variety of common knowledge:     Plants of the new cultivar ‘GRAdkpk’ may be distinguished from the     commercial variety Rosa hybrid ‘GRAppl’ (U.S. Plant Pat. No. 26,364)     by the following combination of characteristics:     -   1. The flowers of ‘GRAdkpk’ exhibit a distinct lavender pink         general tonality, whereas the flowers of ‘GRAppl’ exhibit a         purple general tonality.     -   2. ‘GRAdkpk’ exhibits a petal count of approximately 36 petals,         whereas ‘GRAppl’ typically possesses 22 petals.     -   3. ‘GRAdkpk’ exhibits average leaf dimensions of 8.0 cm long and         6.0 cm wide, whereas (‘GRAppl’ exhibits average leaf dimensions         of 13.5 cm long and 8.5 cm wide.     -   4. Mature field-grown ‘GRAdkpk’ plants exhibit an average plant         height of 100 cm, whereas ‘GRAppl’ exhibits an average plant         height of 120 cm.     -   5. ‘GRAdkpk’ exhibits a rotund plant shape with more twiggy         stems, whereas ‘GRAppl’ exhibits an upright shape with strong         main stems. 

That which is claimed:
 1. A new and distinct variety of Rosa hybrid plant named ‘GRAdkpk’, as described and illustrated herein. 